Heating furnace



Apr. 24, 1923.- 1,452,856

W. TRlNKs HEATING FURNAGE Filed April y 1920 2 Sheets-Sheet l SOHW. y MMM Apr. 24, 1923.

W. TRNKS HEATING FURNACE ,rv 2 Sheets-Sheet 2 Filed April 12, 1920 Patented Apr. 24, 1923.

UNITED rSTATES PATENT OFFICE.

WILLIBALD TRINKS, OF PITTSBURGH, PENNSYLVANIA, ASSIG-NOR TO TATE-J ONES & C0., INC., OF LEETSDALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

HEATING FURNACE.

Application led AprI 1,2, 1920. Serial No. 373,445.

To all whom t may concern:

Be it known that I, VVILLIBALD TRiNKs,

a citizen of the United States, residing in Pittsburgh, in the county of Allegheny, State of Pennsylvania, have invented a new and useful Improvement in Heating Furnaces, of which the following is a specification. A

My improvement relates to the type of furnace in which the material to be heated is carried around on an annular horizontal hearth which revolves about a vertical axis. This type of furnace has appealed to manufacturers, because it is conducive to economy of both fuel and labor. While the rotatinghearth furnace has been a commercial success in small sizes, andv particularly so with l heating by electrical means, furnaces with large hearths have been built, but have in most cases been dismantled and given up, principally on account of breakage, but also on account of unequal distribution of temperature in the case of heating by combustion. The present specification concerns itself principally with the mechanical strength of rotating hearths and with other features contributing to safety against breakage.

In the drawings, Figure 1 is a vertical cross-section thru the center of the furnace, taken in its left hand half thru one of the shafts for entering air, and taken in its right hand half thru the furnace door and thru one of the air discharge ducts. Figure 2 is a plan view, partly in section under the hearth, and in part a top view of the furnace. Figure 3 is an elevation of one of the adjustable bearings; Figure 4 is a front view of the same bearing, while Figure 5 shows the adjusting wedge. Like numerals refer to like parts thruout the different views.

In the illustrations, 1 is the rotating hearth which is built up of metal, with refractory material in the top. 2 are supporting rollers or wheels, which, in my preferred plan, are adjustable up and down by means of wedges 3 and screws 4. For the sake of simplicity, wedges 3 and screws 4 are omitted in Figure 1. The wedges rest on metallic supports 5. The latter are so .10 deep and are spaced so far apart that they leave between them a walking space 6. The outer row of wheels carries flanges against which a depending part of the hearth bears in case of radial thrust. Air is admitted to this walkway thru a plurality of air inlet ducts 7, which are spaced around the cirtroduced into the furnace thru burners 10,

but the method of providing heat for the furnace and of distributing .it evenly is not a part of this invention.

The operation of that part of the furnace which is concerned with the present invention is as follows z-Before the furnace is lighted, all rollers 2 are adjusted to bear uniformly, while the hearth is rotating. This work requires the presence of a man under the hearth and necessitates shifting of the different sections of the furnace up or down relatively to each other in order to make all wheels bea-r in any portion of the hearth. The furnace is then lighted, and loaded with the average weight which is to be heated.

It is during this time that the value of my arrangement becomes evident. Large, slowly-rotating hearths have different temperatures at different part-s of the circumference, because cold material is charged at one spot and hot material is removed at another spot. A heat wave is sent into the top of the hearth by this action at a given spot, and the hearth Warps in such a manner that certain spots-fixed with regard to space-are raised and others are depressed, in a manner which cannot be determined by calculation. If the initial adjustment of the rollers is maintained, the table cracks, because only a few of the supports will bear. A cracked table sticks, and in a short time the whole driving mechanism is ruined. It is this action which has heretofore kept furnaces with large rotating hearths from being successful, although many patents have been granted on that type of furnace.

The problem can be solved only by up and down adjustment of the rollers while the furnace is in operation. To that end I provide under the table 1 sufiicient space 6 for a man to work between the supporting bearings, and I provide entrance shafts 7 leading to the space under the table. The temperature in which a man 'can work for any length of time is much below the temperature in which the rollers under the furnace can work right along,but there are limits to that latter temperature. It is, therefore, very desirable to adjust both the normal operating temperature under the hearth and the temperature which is to prevail during periods of inspection and repair. To that end I partly cover each vertical shaft 7, for instance with sheets, so that the flow o'l air through the space 6 may be regulated. I also provide ducts 8 leading from said space 6 to the stack 9. There being a plurality of air shafts 7 and of ventilatorducts 8, a positive air circulation is obtained. Further regulation of the temperature in space Gis obtained by partial obstruction oit'` any one or all ot' ducts 8.v By these various means, a temperature of 400 to 45() degrees Fahrenheit can be maintained during regular operation; while a working temperature can be maintained during periods ot' inspection and adjustment.

The walkway G between the bearings is made deep enough for. a man to walk in a stooped position.

The passing of the flame. or flue gases from the heating chamber above the rotat? ing tabley into the inspection pit below said table is prevented by sand seals 1l at the inner and outer edges as shown in the illustration. fIhe sand seals are necessary for the control of the temperature below the hearth, it being understood that thetemperature below the hearth is kept just, as high as sale operation will permit, for the purpose of reducing heatloss through the hearth.

What I claim as new is:

l. In a heating furnace with an annular, horizontal, rotating hearth table, independent vertically adjustable supports for said table, an enclosed inspection pit below said table, sand seals between the heating chamber and the inspection pit, a plurality of regulable air admission openings at the outer circumference of the inspection pit, and a plurality of ducts leading from said pit to a central stack.

2. In a heating 'furnace with an annular, horizontal, rotating. hearth table an inner row of wheel supports, an outer row of wheel supports, means for independently adjusting the vertical height of the wheel supports, sand seals at the inner and outer edges of the hearth, means for taking up radial thrust caused by the driving.mechanism, and

vmeans for regulating the temperature below the hearth.

3. In a heating furnace with an annular, horizontal, rotating hearth table, independently adjustable roller supports for said table, a closed inspection pit below said table, a plurality of 4regulable air admission openings at the outer circumference of the` VVILLIB ALD TRINKS. 

